• Nuclear Medicine and Molecular Imaging
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• 제42권4호
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• pp.285-291
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• 2008

목적: 심근관류 SPECT에서 자동정량화 소프트웨어를 이용해 관류 및 기능에 대한 객관적이고 재현성 높은 정량 값을 얻을 수 있지만, 이러한 정량값들을 이용할 때는 분절별로 적지 않은 정상변이가 있음을 고려해야 한다. 이 연구에서는 관류에 대한 정량값에서 정상변이를 고려한 새로운 지표들을 유도하고, 이러한 지표들이 임상적 유용성을 가지는지 생존심근 평가를 통해 알아보았다. 대상 및 방법: 심근관류 SPECT에서 관류의 정상변이를 구하기 위해 55명(남:여=28:27)의 관상동맥질환 저확률군을 선정하였다. 이들에게서 $^{201}Tl$ 휴식기/$^{99m}Tc-MIBI$ 부하기 심근관류 SPECT를 실시하고, 20분절 모델을 이용하여 $^{201}Tl$ 휴식기 관류정량값에 대한 각 분절의 평균(m)과 표준편차(SD)를 구하였다. 생존심근 평가를 위해서는 관상 동맥질환을 진단 받고 관상동맥우회로이식술(CABG)을 시행한 환자 48명을 연구대상에 포함하였다. 이들은 수술전 $^{201}Tl$ 휴식기/$^{99m}Tc$-MIBI 부하기 게이트/$^{201}Tl$ 24시간 지연 SPECT을 실시하였고, 수술 3개월 후 추적 게이트 SPECT를 실시하여 생존심근을 판정하였다. 수술 전 $^{201}Tl$ 24시간 지연 SPECT에서 분절별 $Q_{delay}$ (관류정량값), ${\Delta}_{delay}$ ($Q_{delay}$ - m), $Z_{delay}$ (($Q_{delay}$ - m)/SD)가 정의되었고 이들의 생존심근에 대한 진단성적은 수신자특성곡선 상의 곡선하면적(AUC)을 통해 평가하였다. 결과: 관류정량값은 분절 사이에 상당한 변이를 보여, 남자의 경우 최저치 분절에서 $51.8{\pm}6.5$, 최고치 분절에서 $87.0{\pm}5.9$였고, 여성의 경우 최저치 분절 $58.7{\pm}8.1$, 최고치 분절 $87.3{\pm}6.0$으로 나타났다. 생존심근에 대한 진단성능 평가에서 $Q_{delay}$의 AUC는 0.633인데 반해 ${\Delta}_{delay}$와 $Z_{delay}$의 AUC는 각각 0.735와 0.716으로 나타나 $Q_{delay}$에 비해 유의하게 높은 값을 보였다(각각 p=0.001, 0.018). 가장 높은 AUC를 보인 ${\Delta}_{delay}$는, 최적분리점 -24.7에서 85%의 예민도와 53%의 특이도를 가지는 것으로 나타났다. 결론: 심근관류 SPECT의 자동 정량화 분석에서 관류정량값의 정상변이는 분절에 따라 상당한 것으로 나타났다. 이들을 고려하여 유도된 정량적 지표들은 직접적인 관류정량값에 비해 생존심근 진단에서 더 나은 진단성적을 보였다. 이 연구는 심근관류 SPECT의 정량적 분석에서 정상변이의 고려가 중요함을 시사한다.

• 영어어문교육
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• 제12권3호
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• pp.123-145
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• 2006

The purpose of this study is to propose an efficient vocabulary assessment model in task-based language learning and to verify the viability of this assessment model. Bachman and Palmer (1996) pointed out the fact that many language tests focus on just one of the areas of language knowledge. However, researchers suggested that it is necessary to acknowledge the needs of several analytic scales, which can provide separate ratings for different components of the language ability to be tested. Although there were many studies which tried to evaluate the various aspects of vocabulary ability, most of them measured only one or two factors. Based on previous research, this study proposed an assessment model of general construct of vocabulary ability and tried to measure vocabulary ability in four separate areas. The subjects were two classes of university level Korean EFL students. They participated in small group discussion via synchronous CMC. One class used a lexically focused task, which was proposed by Kim and Jeong (2006) and the other class used a non-lexically focused task. The results showed that the students with a lexically focused task significantly outperformed those with a non-lexically focused task in overall vocabulary ability as well as four subdivisions of vocabulary ability. In conclusion, the assessment model of separate ratings is a viable measure of vocabulary ability and this can provide elaborate interpretation of vocabulary ability.

• 대한핵의학회지
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• 제32권4호
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• pp.325-331
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• 1998

목적: 급성 심근 경색환자에서 생존 가능심근을 찾는데 있어서 부하-재분포와 부하-24시간 재주사 T1-201 SPECT 영상을 비교분석하였다. 대상 및 방법: 급성 심근경색의 진단으로 입원하여 재관류술 시행전 핵의학과에 심근관류 영상을 의뢰한 43명의 환자를 대상으로 하였다. 혈관 확장술이나 관동맥우회로술 이전에 급성 심근경색 발생 후 평균 $10{\pm}5$일에 디피리마몰 T1-201 SPECT를 시행하였다. 심근의 영역을 16개 영역으로 나누어서 부하-재분포 및 부하-재주사 영상을 4등급으로 육안적으로 평가하였다. 심근생존능은 부하영상에서 중등도나 정상섭취를 보이는 경우와, 부하영상에서 섭취가 없거나 심한 관류결손을 보이지만 재분포나 재주사 영상에 1등급이상 관류의 호전이 있어서 가역성 관류결손이 있을 때로 정의하였다. 각 분절의 부하-재분포 및 부하-24시간 후 재주사 영상에서 관류상태를 평가하여 두 평가방법에 의한 차이를 알아보았다. 결과: 육안분석에 의한 가역성평가에서 중등도 관류감소를 보인 52 분절 중 46 (88.5%)가 부하-재분포 및 부하-재주사 영상에서 일치된 소견을 보였다. 차이를 보인 분절은 5명의 6개 분절이었는데 부하-재분포에서는 비가역적이었지만 부하-재주사에 의해서는 가역성을 보였다. 심한 관류감소나 관류결손을 보인 292 분절 중 224 (16.7%)에서 일치율을 보였다. 차이를 보인 68 분절 중 53개 분절은 부하-재분포에서 비가 역적인 결손을 보였으나 부하-재주사에서 가역성이있는 것으로 평가되었다. 이와 반대로 15분절은 단지 부하-재분포에서만 가역성이 있는 것으로 평가되었고 부하-재주사 영상으로는 비가역성을 보였다. 결론: 급성 심근경색증에서 T1-201 24시간 재주사는 심근생존력을 평가하는데 유용하며, 재분포 영상에 비하여 예민하게 하게 심근생존력을 평가할 수 있다. 그러나 재분포 영상없이 재주사영상만 시행할 경우 생존심근이 비가역적으로 평가될 수 있으므로 재분포 영상과 같이 함께 시행하여야 할 것이다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.106-106
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• 2019

The leaves of Phaleria nisidai Kaneh. have been used as a beverage for tonic and immune-enhancing effect in Palau. Recently, extract of the plants showed anti-diabetic effect in clinical trial and possibility could be used as a medicine for diabetes. However, in vitro and in vivo experiments which elucidate cytotoxicity and biological mechanism have not been studied yet. To begin the series of in vitro and in vivo anti-diabetic studies, we evaluated cell viability of pancreatic beta cell lines to figure it out toxicity of the extract. The leaves of Phaleria nisidai were extracted with distilled water and 70% EtOH, and followed by evaporation and lyophilization. And, MIN6 and RIN-m5F cell lines were used for assessment of cell viability. MTT assay was adopted to evaluated a toxicity. Any of extract and concentration used in this study did not show cytotoxicity in the cell lines. Furthermore, morphological change was not observed. These results means Phaleria nisidai might be a medicinal resource when further biological and safety studies would be performed.

• Journal of Korean Dental Science
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• 제14권2호
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• pp.51-60
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• 2021

Purpose: Measuring viability of a three-dimensional in vitro organotypic human oral tissue model has been suggested as an alternative test method to the oral mucosa irritation test of oral care products. The aim of this study was to investigate the production of two different cytokines using organotypic human oral tissue model following exposure to chemicals that are commonly used in oral care products. Materials and Methods: The organotypic human oral tissues were exposed to ethanol, sodium lauryl sulphate or hydrogen peroxide for 90 minutes. Following exposure, interleukin (IL)-1α and IL-8 productions were assessed and correlated with cell viability testing as well as histology of the organotypic human oral tissues. Result: High levels of IL-8 were released from organotypic human oral tissues in all of the test and control groups without any significant differences between them. In contrast, differences were found in IL-1α release between the test and control groups. Additionally, the trend of IL-1α release corresponded to the phenotypes observed in histological analysis while different trend existed between IL-1α release and cell viability. Conclusion: The study concluded the non-specific release of IL-8 for the assessment of oral care product chemicals' toxicity, while potential of measuring IL-1α cytokine level as the possible alternative test method.

• Geomechanics and Engineering
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• 제17권6호
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• pp.527-534
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• 2019

There have been developed a number of methods to assess the abrasivity of rock materials with the increased use of mechanized rock excavation. These methods range from determination of abrasive and hard mineral content using petrographic thin section analysis to weight loss or development of wear flat on a specified cutting tool. The Cerchar abrasivity index (CAI) test has been widely accepted for the assessment of rock abrasiveness. This test has been considered to provide a reliable indication of rock abrasiveness for isotropic rocks. However, a great amount of rocks in nature are anisotropic. Hence, viability assessment of Cerchar abrasivity test for the anisotropic rocks is investigated in this research. The relationship between CAI value and quartz content for the isotropic rocks is well known in literature. However, a correlation between EQ, F-Schimazek value, Rock Abrasivity Index (RAI) and CAI of anisotropic rocks such as phyllite was done first time in literature with this research. The results obtained with this research show F-Schimazek values and RAI values should be considered when determination of the abrasivity of anisotropic rocks instead of just using Cerchar scratch test.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.635-638
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• 2003

For the acute assessment on biological toxicity of wastewater, surface plasmon resonance(SPR) based cell viability detection was performed using gold surface-confined cell as a result of adhesion-modifying chemicals. Escherichia coli O157:H7 (E. coli O157:H7) was investigated after exposure to EDTA. Cells were immobilized on gold coated slide glass for SPR analysis by the method of cross-linking carboxyl group on the bacterial surface with amine group of poly-L-lysine that had been coupled to the gold surface modified by a self-assembled monolayer of 11-mercaptounde canoic acid (11-(MUA)). Reflective intensity of each flow step was changed with respect to confect of ethylenediaminetetraacetic acid (EDTA) disodium salt and phosphate-buffered saline (PBS) solution. The proposed detection technique can be used for biological toxicity test.

• Toxicological Research
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• 제11권1호
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• pp.103-108
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• 1995

Rat renal proximal tubule suspension was prepared from adult male Sprague Dawley rat (250-300g) by mechanical (non-enzymatical) method and evaluated as a pontential model for mechanistic studies and early screening of nephrotoxicity, using anionic antibiotics (cephaloridine). Cephaloridine (CPL) produced an increase in LDH release into media. This release results from decrease a proximal tubule cell viability and subsequently increase the permeability of cell viability and subsequently increase the permeability of cell membrane. Since loss of intracellular potassium and ATP into media is the sign of disruption of cell membrane, especially basolateral membrane (BLM), CPL induced proximal tubule cell compromise also appear be associated with BLM, maybe $Na^+-K^+$ ATPase. Also seen was significant depression in brush border membrane (BBM) ALP activity and no significantly increase in BBM GGT activities. The inhibition of typical anion, PAH accumulation (especially, CPL 5 mM) and cation, TEA (especially, 4hours incubation) were seen dose dependently. This is because of CPL accumulation in renal proximal tubule and increase of cytotoxicity.

• Restorative Dentistry and Endodontics
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• 제39권1호
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• pp.39-44
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• 2014

Objectives: The purpose of this study was to evaluate in vitro cytotoxicity of the pozzolan cement and other root-end filling materials using human periodontal ligament cell. Materials and Methods: Endocem (Maruchi), white ProRoot MTA (Dentsply), white Angelus MTA (Angelus), and Super EBA (Bosworth Co.) were tested after set completely in an incubator at $37^{\circ}C$ for 7 days, Endocem was tested in two ways: 1) immediately after mixing (fresh specimens) and 2) after setting completely like other experimental materials. The methods for assessment included light microscopic examination, cell counting and WST-1 assay on human periodontal ligament cell. Results: In the results of microscopic examination and cell counting, Super EBA showed significantly lower viable cell than any other groups (p < 0.05). As the results of WST-1 assay, compared with untreated control group, there was no significant cell viability of the Endocem group. However, the fresh mixed Endocem group had significantly less cell viability. The cells exposed to ProRoot MTA and Angelus MTA showed the highest viability, whereas the cells exposed to Super EBA displayed the lowest viability (p < 0.05). Conclusions: The cytotoxicity of the pozzolan cement (Endocem) was comparable with ProRoot MTA and Angelus MTA. Considering the difficult manipulation and long setting time of ProRoot MTA and Angelus MTA, Endocem can be used as the alternative of retrofilling material.

• Forest Science and Technology
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• 제14권4호
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• pp.160-168
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• 2018

The seeds of Elaeocarpus serratus, a tropical underutilized fruit tree are characterized by hard seed coat and consequent poor water uptake and low germination. To improve the regeneration through seeds, various parameters such as viability of seeds, water uptake, and effect of seed mass on germination and pretreatments were performed using a completely randomized design (CRD). Tetrazolium (TZ) test was conducted using fresh, mature seeds revealed $50{\pm}2.56%$ mean viability. Seeds of different weight classes showed similar pattern of water uptake and the saturation level was achieved at 60 hrs of soaking. Seeds belong to weight class 2.6-3.5g were germinated ($12.5{\pm}1.26%$) with $175{\pm}1.75days$ (d) of mean time taken for germination (MTG). Germination capacity of seeds varied significantly among different populations and Varkala population gave $12.5{\pm}1.1%$ germination with $174.6{\pm}2.5d$ MTG. Among various seed treatments, mechanical scarification was superior in germination and significant reduction in MTG ($p{\leq}0.05$). The mechanical scarification by complete removal of seed coat resulted in $49.2{\pm}1.52%$ germination within a short period of time ($9.52{\pm}0.89d$ MTG). However, the complete removal of seed coat without damaging to embryo is a difficult task. An alternate treatment (Mechanical scarification II) by making cracks on nut faces vertically followed by soaking in distilled water for 24 hrs gave $48.4{\pm}1.73%$ germination with significantly reduced MTG ($12.14{\pm}0.56d$) over unsoaked, untreated control ($6.5{\pm}1.84%$ germination and $197.18{\pm}1.79d$ MTG; $p{\leq}0.05$). This treatment (Mechanical scarification II) is therefore recommended for E. serratus seeds as it can adopt easily and can achieve 7 fold increases in germination over control. The recorded germination through mechanical scarification is in tune with realized viability percentage of the seeds.